// $Id$
//
//  Copyright (C) 2004-2006 Rational Discovery LLC
//
//   @@ All Rights Reserved @@
//  This file is part of the RDKit.
//  The contents are covered by the terms of the BSD license
//  which is included in the file license.txt, found at the root
//  of the RDKit source tree.
//
#include "BoundsMatrix.h"
#include "TriangleSmooth.h"

namespace DistGeom {
bool triangleSmoothBounds(BoundsMatPtr boundsMat, double tol) {
  return triangleSmoothBounds(boundsMat.get(), tol);
}
bool triangleSmoothBounds(BoundsMatrix *boundsMat, double tol) {
  int npt = boundsMat->numRows();
  int i, j, k;
  double Uik, Lik, Ukj, sumUikUkj, diffLikUjk, diffLjkUik;

  for (k = 0; k < npt; k++) {
    for (i = 0; i < npt - 1; i++) {
      if (i == k) {
        continue;
      }
      Uik = boundsMat->getUpperBound(i, k);
      Lik = boundsMat->getLowerBound(i, k);
      for (j = i + 1; j < npt; j++) {
        if (j == k) {
          continue;
        }
        Ukj = boundsMat->getUpperBound(k, j);
        sumUikUkj = Uik + Ukj;
        if (boundsMat->getUpperBound(i, j) > sumUikUkj) {
          boundsMat->setUpperBound(i, j, sumUikUkj);
        }

        diffLikUjk = Lik - Ukj;
        diffLjkUik = boundsMat->getLowerBound(j, k) - Uik;
        if (boundsMat->getLowerBound(i, j) < diffLikUjk) {
          boundsMat->setLowerBound(i, j, diffLikUjk);
        } else if (boundsMat->getLowerBound(i, j) < diffLjkUik) {
          boundsMat->setLowerBound(i, j, diffLjkUik);
        }
        double lBound = boundsMat->getLowerBound(i, j);
        double uBound = boundsMat->getUpperBound(i, j);
        if (tol > 0. && (lBound - uBound) / lBound > 0. &&
            (lBound - uBound) / lBound < tol) {
          boundsMat->setUpperBound(i, j, lBound);
          uBound = lBound;
        }
        if (lBound - uBound > 0.) {
          // std::cerr<<std::endl;
          // for(unsigned int ii=0;ii<npt;++ii){
          //   for(unsigned int jj=0;jj<npt;++jj){
          //     std::cerr<<" "<<std::setprecision(3)<<boundsMat->getVal(ii,jj);
          //   }
          //   std::cerr<<std::endl;
          // }
          // std::cerr<<std::endl;
          // std::cerr<<" Fail: "<<i<<"-"<<j<<": " <<
          // boundsMat->getLowerBound(i,j) << " " <<
          // boundsMat->getUpperBound(i,j) << "\n";
          return false;
        }
      }
    }
  }
  return true;
}
}